Such devices, i.e. intramedullary nails, bone plates, clamping jaws for external fixation devices or intervertebral implants show the problem that there is always a clearance between the through hole and the bone fixation means inserted therein (e.g. locking elements in case of intramedullary nails or bone screws in case of bone plates). In case of an intramedullary nail the locking bolt is loosely guided within the intramedullary nail but not axially fixed. In the axial direction the bolt is neither guided nor fixed.
For example from U.S. Pat. No. 6,296,645 HOVER ET AL. a hollow intramedullary nail made of metal is known which is provided with one or two synthetic inserts in the diametrally arranged shell apertures of the transverse bore holes, the so called windows, where a locking screw may be inserted. This known intramedullary nail shows the disadvantage that the window-like synthetic inserts may be easily busted, therewith loosening the desired function. Even in case of a very cautious manipulation the two synthetic inserts may be pressed out of their “window” upon insertion of the locking screw whereby the inserts may lose their function.